Tampon package and method for making same

ABSTRACT

A sealed tampon package and continuous process for making the package. Heat seals, preferably hermetic longitudinal and cross seals, are preferably peelable. The tampon is sealed under sufficient negative pressure to snugly retain the tampon in place without crushing or misshaping the tampon, yet without bursting the package under normal external pressures realized during storage. The tampon package will remain sealed during normal wear and tear, yet is easily opened when desired by peeling the seals.

BACKGROUND OF THE INVENTION

[0001] The invention relates to a tampon package. More specifically, theinvention is directed to a hermetically sealed, moisture-proof, peelablepackage for storing tampons and for ease of opening.

[0002] Tampons are commonly packaged using a paper wrapping. Such wrapsallow air and moisture to seep through and contaminate the tampon.

[0003] It is also known to package tampons in plastic. However, knownpackages use positive pressure. If pressure is applied to the tampon,the package can burst open. Such packages also may use perforated endswhich can wear apart over time.

[0004] Accordingly, it would be advantageous, and it is an object of theinvention to provide: a tampon package which is sealed in a negativeatmosphere to prevent bursting of the package from external pressure;which provides a hermetically sealed, moisture-proof package; and whichprovides a peelable package whose openings will not wear open over areasonable storage time.

[0005] It would also be advantageous, and is another object of theinvention, to provide a continuous process for packaging tampons in thismanner.

Definition of Claim Terms

[0006] The following terms are used in the claims of the patent as filedand are intended to have their broadest meaning consistent with therequirements of law.

[0007] “Hermetic seal” or “hermetically sealed” means a seal that willexclude air and will be leakproof at normal temperatures and atmosphericpressure to the extent the thermoplastic materials used permit.

[0008] “Peelable” refers to a seal which may be readily manually brokenby a consumer.

[0009] Where alternative meanings are possible, the broadest meaning isintended. All words used in the claims are intended to be used in thenormal, customary usage of grammar and the English language.

SUMMARY OF THE INVENTION

[0010] The objects mentioned above, as well as other objects, are solvedby the present invention, which overcomes disadvantages of prior artpackages and packaging methods, while provided new advantages notpreviously obtainable.

[0011] In one embodiment of the present invention, a sealed tamponpackage is provided using a length of thermoplastic material entirelyenclosing the tampon and formed into a wrapper. The wrapper may includetop and bottom web portions. The bottom web portion may be comprised ofan extensible, thermoformed material. The wrapper preferably includestwo opposed longitudinal seals formed along its length and two opposedcross-seals. These seals may be heat seals, and preferably are hermeticheat seals. The seals may be formed by applying pressure at sealingzones located at opposed edges on the package and heating the sealingzones to a temperature and for a time sufficient to form longitudinaland cross seals that are hermetic around the entire periphery of thepackage. The hermetically sealed, individually wrapped tampon is undernegative pressure, such as in the range of 8-20 inches of Mercury, andmore preferably in the range of 10-15 inches of Mercury, in an amountsufficient to retain the tampon snugly within the package withoutcrushing or misshaping the tampon. At least one of the cross-sealsand/or the longitudinal seals is peelable, preferably withoutdelamination of the thermoplastic material. The peelable sealspreferably have a peel strength in the range of 600-800 grams/inch ofwidth.

[0012] Various alternative film materials may be manufactured andformulated for use as the package material. For example, thethermoplastic film may consist of an extruded film, or a solution castor calendered material. Further, the top web portion may be made of alinear low density polyethylene material comprising an ethylene vinylacetate/polyisobutylene blend, while the bottom web portion may be madeof a nylon/low density polyethylene blend.

[0013] In an alternative embodiment, the cross-seals may include one ormore notches to facilitate opening of the package. Tear tape may also beused to facilitate package opening.

[0014] In another embodiment, the package may include a flow-throughstyle wrapper in which negative pressure on the tampon is provided usinga gas flush technique.

[0015] In another preferred embodiment, the invention consists of acontinuous process for hermetically packaging a tampon, in which acontinuous web of heat-sealable thermoplastic material is formed into afirst wrapper which entirely encloses the tampon. As the web iscontinuously moved in a forward direction, portions of the web peripherysurrounding the tampon are heated and pressured in a sufficient amountto form hermetic longitudinal and cross seals so that the tampon isentirely surrounded by the hermetically sealed plastic web to form ahermetically sealed package. The hermetic seals are formed in acontinuous manner as the web is moved forward, and are peelable.Negative pressure is applied to the tampon within the package in therange of about 8-20 inches of Mercury. Negative pressure may be appliedusing a gas flush technique. Preferably, the peel strength of thepeelable seals is in the range of 600-800 grams/inch of width.

[0016] In an alternative embodiment, the tampon may first be packaged ina second, inner wrapper, which may be made of a paper-based material,prior to being packaged within the first wrapper.

BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The novel features which are characteristic of the invention areset forth in the appended claims. The invention itself, however,together with further objects and attendant advantages thereof, will bebest understood by reference to the following description taken inconnection with the accompanying drawings, in which:

[0018] FIGS. 1-4 are side perspective views of various embodiments ofthe tampon package invention; and

[0019]FIG. 5 is a sectional view along reference line 5-5 of FIG. 4.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] Set forth below is a description of what is currently believed tobe the preferred embodiment and/or best example of the inventionclaimed. Future and present alternatives and modifications to thispreferred embodiment are contemplated. Any alternatives or modificationswhich make insubstantial changes in function, in purpose, in structureor in result are intended to be covered by the claims of this patent.

[0021] In accordance with a preferred embodiment of the invention, apackaged tampon, generally referred to as 10, is shown in FIG. 1.Package 10 preferably incorporates the advantages of the inventiondescribed above, and may include an extensible, thermoformed,longitudinal bottom web 15 designed to snugly hug the tampon, a top web17 which forms the opposing longitudinal side of the package, andopposing ends 20, 21. One of the webs, preferably the top web, may becolorized if desired. A peelable heat seal, preferably a hermetic seal,may be provided. Use of hermetic longitudinal seals 25 and hermeticcross-seals 26 will insure that the tampon is entirely, hermeticallyenclosed within the package.

[0022] “Peelable” refers to a seal which may be readily, manually brokenby the consumer; preferably no rupturing or tearing of the film occursduring peeling, though this is not a requirement of the invention.Unsealed opposing flaps 20A, 20B may be provided at one end of thepackage to facilitate peeling open the heat sealed package. At least oneof the cross-seals and/or the longitudinal seals is preferably peelablewithout delamination of the thermoplastic material. A seal may also beprovided which is peelable by delaminating layers of film in alamination, i.e., the bond strengths in the lamination are designed togive way when subjected to peel force. Preferably, the opposing endsintersect in a hermetic seal which is sufficiently strong so that merestorage, normal handling or the passage of time will not wear away theseal and cause it to unintentionally open. The hermetic seal may beadhesive (i.e., referring to a seal failure mode in which a film sealantlayer(s) separate from a base or substrate film layer) or cohesive(i.e., referring to a seal failure mode in which portions of a filmsealant layer(s) separate from itself/themselves) in nature. Cohesivefailure peel seals may be created using polyisobutylene, which preventsthe plastics at the sealing interfaces from tightly commingling andallows them to peel apart without tearing film. Cohesive seals may, whenpeeled, leave a discoloration, which may or may not be desirable. Thehermetic seal preferably falls within the following negative pressureranges: 8-20, and more preferably 10-15, inches of Mercury as determinedthrough visual observation in a bell jar. Preferably, the tampon issealed in a negative atmosphere sufficient to prevent bursting of thepackage from external pressure, and also sufficient to maintain ahermetic seal, yet not so strong as to constrict or misshape the tampon.23-25 inches of Mercury was determined to be excessive negative pressurewhich crushed the tampon. The peel strength of the heat seals ispreferably in the range of 600-800 grams/inch of width.

[0023] In an alternative embodiment, an easy-open feature may beprovided. Thus, as shown in FIG. 2, Zip opening tear tape 32 may beemployed to facilitate opening of package 10. One or more tear notchesmay be also be provided, as shown in FIG. 3, designed to tear linearly,and may be used with or without tear tape.

[0024] In yet another alternative embodiment, a flow-through stylewrapper using vacuum or gas flush may be provided. For example, anitrogen-carbon dioxide gas mixture may be introduced into the tube,such that as the carbon dioxide escapes from the film (the nitrogen,with its larger molecules, will do so more slowly over time), the filmwill fit snugly against the tampon. The degree of snugness can bemodified given the gas mixture and the film permeation rates.

[0025] Alternatively, as shown in FIG. 4, the tampon 12 may be packagedin a paper, “inner” wrapper 40, which is then packaged in a plastic“outer” wrapper as described above. The inner wrapper is not a necessarypart of the invention, however.

[0026] One film material 50 suitable for forming a top web and providinga peelable seal is 48 BOPet (biaxially oriented polyester) adhesive, 2mil. LLDPE (linear low density polyethylene, EVA (ethylene vinylacetate)-PIB (polyisobutylene) blend), coextrusion. EVA/PIB blend isused to provide peel seal properties. Other suitable films for forming atop web and providing a peelable seal include:

[0027] 48 BOPet/7#LDPE/1.5 mil LLDPE (EVA-PIB blend) coextrusion, whereLDPE is low density polyethylene

[0028] 60 BON/adhesive/2 mil LLDPE (EVA-PIB blend) coextrusion, whereBON is biaxially oriented nylon

[0029] 60 BON/7# LDPE/1.5 mil. LLDPE (EVA-PIB blend) coextrusion

[0030] 80 BOPP/adhesive/2 mil. LLDPE (EVA-PIB blend) coextrusion, whereBOPP is biaxially oriented polypropylene

[0031] 80 BOPP/7# LDPE/1.5 mil. LLDPE (EVA-PIB blend) coextrusion

[0032] A thermoformable bottom web may be provided using one of thesefilms, for example:

[0033] 3-3.5 mil. Nylon/tie/LLDPE coextrusion

[0034] 2-2.5 mil. Nylon/adhesive/1 mil. LLDPE

[0035] 2-2.5 mil. formable PET/adhesive/1 mil. LLDPE, where PET ispolyester.

[0036] While non-oriented substrate film layers are currently preferred(to avoid additional film processing steps, and also because cast filmstend to be lower cost), there may be some advantage in a particularapplication to using an oriented film, which may be stronger than anon-oriented film.

[0037] Various additives may be provided to the film for differentpurposes. Processing aids such as slip and antiblock additives may alsobe used as needed. Slip or coefficient of friction (COF), the measure ofhow easily or difficult a film surface slips upon itself. Typically,films with COFs in the range of 0.1 to 0.3 (high to medium slip) aresuitable for high speed automatic wrapping machines.

[0038] Of course, those of ordinary skill in the art will realize thatother film formulations can be used to accomplish the general objectivesof the present invention. Potential film substrates may includepolyethylene and its variants (such as EVA (ethylene vinyl acetate), EMA(ethylene methyl acrylate), EEA (ethylene ethyl acrylate), HDPE, LDPE,LLDPE, linear LDPE, and metallocene polyethylenes), polypropylene,paper, nylon, cellophane, polyester, aluminum foil, polystyrene oracrylonitriles. Potential sealant layer compositions may includepolyethylene and its variants, as well as waxes and other food-safeadhesives or coatings such as ionomers, polybutylene, acid-modified EVA,EMA, tackifiers such as terpenes, synthetic waxes and polyisobutylene.

[0039] Film processing techniques that can be utilized to providepackaging films useful with the present invention include, but are notlimited to, extrusion, coextrusion, extrusion coating, lamination anddry lamination, for example.

[0040] It will be understood by those of ordinary skill in the art thatthe efficacy of a heat seal is a function of dwell time, sealingtemperature and sealing pressure. It will also be understood that theparticulars of such time, temperature and pressure will vary dependingupon such variables as the film selected, the desired speed, the fooditem selected, the sealing equipment used, and the desired sealcharacter.

[0041] Persons of ordinary skill in the art will understand that,typically, packages of the present invention will be made using ahorizontal thermoform machine, as well known in the art. However, it isalso understood that the present invention may be adapted for use withvertical fill-and-form machines, as well.

[0042] Those of ordinary skill in the art will appreciate that theparameters involved in food packages may differ from non-food packagesin some respects. Food packages generally require low oxygen andmoisture permeation rates, i.e., 1 cc or less of oxygen per 100 sq.inches/24 hours, and 1 gram or less of moisture per 100 sq. inches/24hours. Hermetically sealed food packages are an obvious preference tomaintain low oxygen and moisture quantities within the packagethroughout its handling and distribution cycle. Hermetic seals providesanitary advantages for tampon packaging, as well. Direct contactfoodpackaging materials must meet FDA regulations spelled out in Rule 21 ofthe Code of Federal Regulations. Finally, the design of food packagingequipment must incorporate features to minimize potential for foodcontamination, i.e., stainless steel food contact surfaces anddisassembling features to assure effective cleaning.

[0043] The above description is not intended to limit the meaning of thewords used in the following claims that define the invention. Rather, itis contemplated that future modifications in structure, function orresult will exist that are not substantial changes and that all suchinsubstantial changes in what is claimed are intended to be covered bythe claims.

We claim:
 1. A hermetically sealed tampon package, comprising: a lengthof thermoplastic material entirely enclosing the tampon, thethermoplastic material formed into a wrapper; the wrapper having twoopposed hermetic longitudinal seals formed along its length and twoopposed hermetic cross-seals, the seals being formed by applyingpressure at sealing zones located at opposed edges on the package andheating the sealing zones to a temperature and for a time sufficient toform longitudinal and cross seals that are hermetic around the entireperiphery of the package; wherein a hermetically sealed individuallywrapped tampon is produced which is under negative pressure sufficientto retain the tampon snugly within the package without crushing ormisshaping the tampon, and also sufficient to prevent bursting fromnormal external pressures exerted on the tampon during storage; andwherein at least one of the cross-seals and the longitudinal seals arepeelable.
 2. The tampon package of claim 1, wherein the seals arepeelable using cohesive or delamination designed failures.
 3. The tamponpackage of claim 3, wherein the negative pressure is in the range of8-20 inches of Mercury.
 4. The tampon package of claim 3, wherein thenegative pressure is in the range of 10-15 inches of Mercury.
 5. Thetampon package of claim 1, wherein the peelable seals have a peelstrength in the range of 600-800 grams/inch of width.
 6. The tamponpackage of claim 1, wherein the wrapper comprises top and bottom webportions, wherein the bottom web portion comprises an extensible,thermoformed material.
 7. The tampon package of claim 6, wherein the topweb portion comprises a linear low density polyethylene materialcomprising an ethylene vinyl acetate/polyisobutylene blend.
 8. Thetampon package of claim 6, wherein the bottom web portion comprises anylon/low density polyethylene blend.
 9. The tampon package of claim 1wherein at least one of the cross-seals includes one or more notches tofacilitate opening of the package.
 10. The tampon package of claim 1,the package further comprising tear tape to facilitate its opening. 11.The tampon package of claim 1, wherein at least one of the longitudinalsides of the package comprises an extensible, thermoformed plasticmaterial.
 12. The tampon package of claim 1, wherein the packagecomprises a flow-through wrapper and negative pressure is provided usinga gas flush technique.
 13. The tampon package of claim 1, wherein thethermoplastic film comprises an extruded film.
 14. The tampon package ofclaim 1, wherein the thermoplastic film comprises a solution cast orcalendered material.
 15. A sealed tampon package, comprising: a lengthof thermoplastic material entirely enclosing the tampon, thethermoplastic material formed into a wrapper; the wrapper having twoopposed longitudinal heat seals formed along its length and two opposedcross-seals comprising heat seals, the heat seals being formed byapplying pressure at sealing zones located at opposed edges on thepackage and heating the sealing zones to a temperature and for a timesufficient to form longitudinal and cross heat seals around the entireperiphery of the package; wherein a heat sealed individually wrappedtampon is produced which is under negative pressure sufficient to retainthe tampon snugly within the package without crushing or misshaping thetampon; and wherein at least one of the cross-seals and the longitudinalseals is peelable.
 16. A continuous process for hermetically packaging atampon, comprising: forming a continuous web of heat-sealablethermoplastic material into a first wrapper which entirely encloses thetampon; continuously moving the web in a forward direction; heating andpressuring portions of the web periphery surrounding the tamponsufficient to form hermetic longitudinal and cross seals such that thetampon is entirely surrounded by the hermetically sealed plastic web ina hermetically sealed package, the hermetic seals being formed in acontinuous manner as the web is moved forward, the hermetic seals beingpeelable; and applying negative pressure to the tampon within thepackage in the range of about 8-20 inches of Mercury.
 17. The continuousprocess of claim 16, wherein negative pressure is provided using a gasflush technique.
 18. The continuous process of claim 16, wherein thepeel strength of the peelable seals is in the range of 600-800grams/inch of width.
 19. The continuous process of claim 16, wherein thetampon is first packaged in a second, inner wrapper prior to beingpackaged within the first wrapper.
 20. The continuous process of claim16, wherein the second, inner wrapper comprises a paper-based material.